Orientation compass



' Dec. 14, 1943. A JoNssoN ORIENTATION COMPASSl Filed nay 4", 1942 2 -Shee'lzs-Shee't 1 De. 14, 1943. V JQNSSQN 2,336,790

ORIENTATION COMPASS Filed nay 7. 1942. 2 sheets-sheet 2 Fatented Dec. 14, 1943 l] N i TED SSTAT man 'TENT OF Fl CE Applieation'May 7, 1942, SerialNo. 442,101 vIn Sweden January 24, 1941 SiClaims.

The object of the present invention refers more particularly to orientation Compasses of the type which are provided with a compass-box rotatably mounted in a base which, with the exception of the part which indicates the marching direction, is substantially circular. The invention is characterized by the feature that there are provided on the compass-box a number of parallel lines the terminal points of which are situated at the periphery of the compass base and which consist of the edge lines of a number or" diierently coloured plates or elds provided on the compass-box. The invention greatly facilitates the procedure of making out the course, and the risk of incorrect setting is practically eliminated.

The invention will be more particularly described in the following with reference to the accompanying drawings, in which Figure l is a plan view of an orientation compass according to the invention, placed on a map, and

Figure 2 is a section along the line II-II in Figure 1.

Figure 3 is a top plan View of a second embodie ment of orientation compass according to the present invention, and

Figure 4 is a section along line IV-IV in Figure 3.

Corresponding reference numerals designate corresponding parts throughout the several iigures of the drawings.

In the drawings, Iv designates the base of the compass which is annular and from which tangentially projects a rule 2 which in a well-known manner serves to indicate the marching direction. The compass base I with the rule 2 may be made from any suitable transparent or opaque material. In the base I is rotatably mounted a box 3 of Celluloid, in which a compass-needle '5 is supported on a pivot l in well-known manner. On the tcp and bottom oi the compass-box 3 is xed a circular disc E or i, respectively, said discs serving as a guide.

one is of transparent material, e. g. Celluiolcl, and has the same or approximately the same diameter as the outer diameter of the compass bac-e i. On this upper disc 6 there are provided a Lumber of bearing lines 9, I, II running parallel with the north-south mark 8 of the compassbox 3. These lines are formed, in the example shown, or" the edge lilies of six differently coloured elds Id, I5, i6 situated in two groups I2, i3 on either side of the Window 2B of the lled with liquid and preferably made Of these discs at least the compass-box. `The elds may advantageously consist of thin strips of coloured Celluloid glued on to the disc 6, the parallel edge lines 9, I G, I I of which extend over the whole disc. The edge surface of the disc 6 as well as the end surfaces of the Celluloid strips should be serrated or riiied to facilitate the rotation of the compass-box 3.

When the course is to be made out between the two places A and B on the map I8, the compass is placed so that the two points are situated along one of` the longitudinal edges of the rule 2, whereupon the compass-box 3 is rotated while at the same time moving the compass in the iongitudinal direction of the rule, until one of its bearing lines, for example the line I0 to the left in the drawing, coincides with one of the merdians I9 of the map I3. As will be seen from Figure 1, said bearing line IEJ is in alignment with the meridian I 9 in question. The marching direction is indicated in the well-known manner by the direction of the rule 2, when the north end of the compass-needle 5 points towards the north-south mark 8.

It will be understood that with the new compass it has been made possible to make out the course very rapidly but yet precisely. Owing to the particular construction of the compass base i and the tangentially projecting rule 2 the map is made freely surveyable, and the compass can be conveniently held in one hand for example during an orientation race. Furthermore, the compass can be rapidly and easily wiped, if for some reason it should have been soiled during use, and the bearing lines 9, IE), II stand out very clearly even in bad weather owing to the differently coloured fields I d, I5, I6.

The form of construction described above is only an illustrative example, and the various elements of the compass can naturally be altered in many ways within the scope of the invention. Thus, as shown in Figs. 3 and 4 of the drawings, the dierently coloured fields need not necessarily be provided on the top side of the compass-box. In the case of a quite transparent compass-box 3', which moreover need not have the same diameter as the compass base I-possibly with the exception oi the bottom-the differently coloured plates or fiel-ds I4', I5', I6' may be provided on said bottom, so that the terminal points of the edge lines are situated at the periphery of the compass base. The compass-box will then be situated wholly above the compass base in which it may be rotatably mounted in any suitable manner, for example on a pivot 4'.

What I claim and desire to secure by Letters Patent is:

1. In an orientation compass of the character described, the combination with a substantially circular compass base and a compass-box rotatably mounted in said base and having a northsouth line, of rule means projecting from said compass base, and means provided on said compass-box and on said base forming a number of juxtaposed, rectilinear, differently-colored fields, the edge lines of said elds being para11e1 With each other and with the north-south line and extending to the periphery of the compass base and serving as bearing lines, and at least one of said means and said compass-box being transparent.

2. In an orientation compass of the character described, the combination with a substantially circular compass base and a compass-box rotatably mounted in said base and having a northsouth line, of rule means projecting from said compass base, and means provided on the top of said compass-box and on said base forming a number of juxtaposed, rectilinear, differently-colored transparent elds, the edge lines of said fields being parallel with each other and with the north-south line and extending to the periphery of the compass base and serving as bearing lines.

3. In an orientation compass of the character described, the combination with a substantially circular compass base and a transparent compass-box rotatably mounted in said base and having a north-south line, of rule means projecting from said compass base, and means provided on the bottom of said compass-box and on said base forming a number of juxtaposed, rectilinear, differently-colored fields, the edge lines of said elds being parallel with each other and With the north-south line and extending to the periphery of the compass base and serving as bearing lines.

ARVID J ONSSON. 

